limits de funcions II

lim [ x --> a ]-[ ( (x^{2}+(-1)·a^{2})/(x+(-a)) ) ] = 2a
lim [ x --> (-a) ]-[ ( (x^{2}+(-1)·a^{2})/(x+a) ) ] = (-2)a


lim [ x --> ai ]-[ ( (x^{2}+a^{2})/(x+(-a)i) ) ] = 2ai
lim [ x --> (-a)i ]-[ ( (x^{2}+a^{2})/(x+ai) ) ] = (-2)ai


lim [ x --> 1 ]-[ ( ( a_{1}x+...(n)...+a_{n}x^{n}+(-1)·∑ ( a_{k} ) )/(x+(-1)) ) ] = ∑ ( a_{k}·k )
lim [ x --> 1 ]-[ ( ( a_{1}x+...(n)...+a_{n}x^{(1/n)}+(-1)·∑ ( a_{k} ) )/(x+(-1)) ) ] = ∑ ( a_{k}·(1/k) )